In a classic experiment in the 1980s, the cells of three mouse embryos were intermingled at the 8-64 cell stage; they clustered and became one mouse called a chimera with different parts showing the features of its six different parents! What does this indicate relative to the independence of one individual cell as the smallest unit of life? When researchers intermingled the cells of four or five embryos, only traits from three parental lineages were expressed in the chimera. Why? Why would the distribution of mouse embryo-versus-placenta cells not be 50-50 or even less for the placenta?